Clamping tool

ABSTRACT

The clamp ( 1 ) is intended for securing a workpiece to an agricultural implement, in particular for securing a cultivator tine to a frame member, and comprises a piece of steel sheet which by bending ( 4 ) is divided into two legs ( 2, 3 ), one leg ( 2 ) of which has an aperture ( 5 ) with an edge ( 8 ), which is substantially positioned in a plane, for receiving a part of a workpiece to be secured, the sheet material comprising along the edge ( 8 ) a part ( 9 ) extending towards the bending ( 4 ) and a remaining part ( 10 ) extending around the aperture ( 5 ) and extending from, and preferably substantially perpendicular to, the plane of the aperture edge ( 8 ) in a direction away from the second leg ( 3 ).

CROSS REFERENCE TO RELATED APPLICATION

The present application is the national stage under 35 U.S.C. 371 ofPCT/DK99/00054, filed Feb. 3, 1999.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to a clamp for securing a workpiece to anagricultural implement, in particular for securing a cultivator tine toa frame member, comprising a piece of steel sheet which by a bending isdivided into two legs, one leg of which has an aperture through thesteel sheet with an edge, which is substantially positioned in a plane,for receiving a part of a workpiece to be secured, in particular an endof a cultivator tine or a tine spring, the sheet material comprisingalong the edge a part extending towards the bending and a remaining partextending around the aperture.

2. Prior Art

Such a clamp is known for instance from GB-A-2 050 131, which disclosesa clamp made from a rectangular piece of steel sheet which is providedwith two apertures, one for receiving the end of a cultivator tine andone for receiving a bolt with a tapered head for clamping the second legof the clamp and the end of the cultivator tine around a frame member,to which the cultivator tine is to be secured. The effect of using abolt with a tapered head is that the first leg of the clamp is tightenedagainst the frame member.

DK 101 615 C discloses a clamp for securing a cultivator tine to a framemember and being made from a piece of steel bar which is bent into akink and two branches the latter being held together by a clamping blockwhen the clamp is used. When in use the kink entends around thecultivator tine and the branches extends over the frame member.

OBJECT AND SUMMARY OF THE INVENTION

The object of the invention is to provide an improved clamp.

The object is met by a clamp of the type mentioned by way ofintroduction which is characterized in that the remaining part of thematerial around the aperture extends out of, and preferablysubstantially perpendicular to, the plane of the aperture edge in adirection away from the second leg.

The result is that the width of the clamp can be reduced to the width ofthe workpiece to be secured, and twice the thickness of the sheetmaterial, which is an advantage as it provides a higher degree offreedom for the lateral positioning of for instance a cultivator tine ona frame member. Moreover, a saving of material is obtained, as the widthof the second leg of the clamp may be smaller than usual. Finally, abigger abutment surface against the workpiece to be fastened isobtained, as the sheet material of the clamp around the aperture hasbeen turned 90° in comparison with known clamps and bears flatly againstthe workpiece to be fastened.

The second leg preferably has an aperture for receiving a clamping bolt,and a part of the sheet material adjacent to this aperture has beenpressed down to the same side as the first leg, the result being aninclining transition from the part, which has been pressed down, to theremaining part of the second leg. By clamping, the inclining transitionbetween the part, which has been pressed down, and the remaining part ofthe second leg of the clamp will have the same effect as the bolt withthe tapered head used according to the above-mentioned GB-A-2 050 131,which makes it possible, with the clamp according to the invention, touse an ordinary standard bolt instead of the tapered, special bolt,which results in economy saving when replacing the bolt in case ofruptures.

The aperture in the first leg preferably forms a substantially isoscelestriangle with round corners and its vertex facing the second leg. Inthis way an advantageous distribution of the tensions in the material isobtained.

The clamp preferably has a degree of hardness in the range of 43-49 HRC.

The object of the invention is further met by a method for themanufacture of a clamp according to the invention, which ischaracterized in that a plane steel sheet blank with a first and asecond end is provided, the first end being provided with a throughgoingaperture with an edge, a part of the material of the blank along theedge extending towards the other end of the blank, the remaining partextending around the aperture, and that the remaining part bytemperature deformation is bent out of the plane of the blank,preferably to a position substantially perpendicular to the plane of theblank and that the blank is angularly bent.

Preferred embodiments of the method appear from the dependent claims6-9.

The invention also relates to an agricultural implement, in particular acultivator with a member clamped on a frame member, the member beingclamped by means of a clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in detailed in the following by means ofan example of an embodiment with reference to the drawing, in which

FIG. 1 is an isometric view of a clamp,

FIG. 2 shows a blank for the manufacture of the clamping means prior toshaping,

FIG. 3 shows the blank according to FIG. 2 after the deformation of thematerial around the aperture in the first leg,

FIGS. 4-6 show the finished clamp, seen in three mutually perpendiculardirections,

FIG. 7 is a sectional view along the line VII—VII in FIG. 6, and

FIG. 8 illustrates the use of the clamp.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

FIGS. 1 and 4-8 show a clamp 1 with a first leg 2 and a second leg 3,the first and the second legs 2, 3 meeting in a bending 4.

The first leg is provided with an aperture 5 for receiving the end of amember, for instance a cultivator tine spring 6, which is to be clampedon a frame member, like for instance a square tube, of an agriculturalimplement.

The aperture 5 is defined by an edge 8, positioned in the plane p of thefirst leg 2. A part 9 of the material of the clamp bordering the edge 8,extends towards the bending 4, whereas a remaining part or sidewall 10of the material bordering the edge 8 is bent approx. 90° to a positionperpendicular to the plane of the edge 8, as will appear from thefigures.

The end 11 of the second leg 3 opposite the bending 4 is provided withan aperture 12 for receiving a bolt as shown in FIG. 8. The area 13 nextto the aperture 12 has been pressed down to the side, in which the firstleg 2 extends, whereby inclining areas 14 have been provided between theareas 13, which have been pressed down, and the remainder of the secondleg 3.

At the bending 4, a bulging 15 has been created, said bulging beingknown per se.

The clamp is used in a manner known per se as shown in FIG. 8, acultivator tine spring 6 being fastened to a square tube 7 by means ofthe clamp 1 and a bolt 16. The cultivator tine spring 6 is passedthrough aperture 5 in the first leg, and the bolt 16 extends through ahole in the cultivator tine spring 6 and through the aperture 12 in theclamp to clamp these two members around the square tube 7. The incliningareas 14 abut a corner 17 of the square tube 7 and thereby pull thefirst leg 2 into abutment against the side 18 of the square tube.

On account of the part 10 being bent, a relatively big abutment surfaceis obtained between the clamp 1 and the cultivator tine spring 6relative to what is obtained by the known clamps, a smaller surfacepressure resulting.

As will in particular appear from FIG. 4, the clamp 1 is only twice thematerial thickness of the part 10 wider than the aperture 5, which inturn is dimensioned according to the cultivator tine spring 6 or anothermember, with which the clamp is to be used. The clamp 1 according to theinvention is thus narrower than similar known clamps. It is advantageousas it leaves more space for obtaining the exact positioning of thecultivator tine spring 6 along the square tube 7, which may carry manyother members than cultivator tine springs.

The bulging 15 acts in a manner known per se to take up manufacturingtolerances between the square tube 7 and the clamp 1, and to prevent thesecond leg 3 from being brought first into abutment against the squaretube 7 close to the bending 4, which would give a too big clamping forcein the first leg 2 of the clamp.

The clamp 1 is manufactured by cutting out a clamp blank 1′ from a steelsheet having an aperture 5′ at one end 2′, and an aperture 12′ at theother end 3′. The aperture 5′ is narrower than the aperture 5 in thefinished workpiece. Through temperature deformation a part 10′ of theblank 1′ is bent, said part extending around the aperture 5′, approx.90°, such that the blank 1′ is given the shape shown in FIG. 3, in whichthe part 10′ extends upwards from the plane of the drawing. Thedeformation is substantially a stretching deformation. Then the areasaround the aperture 12′ are pressed down, and the blank 1′ bent into thedesign shown in FIGS. 1 and 4-8. Finally, the blank is tempered to ahardness of 43-49 HRC.

What is claimed is:
 1. A clamp for securing a workpiece to anagricultural implement comprising a piece of steel sheet which by abending is divided into a first leg and a second leg, the first legcomprising a part, a remaining part, and an aperture through the pieceof steel sheet, the aperture having an edge, said edge beingsubstantially positioned in a plane, the first leg having, along saidedge, the part extending towards the bending and the remaining partextending around the aperture, wherein the remaining part is formed as asidewall extending on opposite sides of the part; and on a side of theaperture opposite the bending, the sidewall extending towards thebending, and out of the plane of the edge in a direction away from thesecond leg.
 2. A clamp according to claim 1, wherein the second leg hasan aperture for receiving a clamping bolt, the piece of steel sheetcomprising a depression on either side adjacent to the aperture of thesecond leg extending towards the first leg, and an inclining transitionfrom the depression to a remainder part of the second leg (3).
 3. Aclamp according to claim 1, wherein the aperture in the first leg formsa substantially isosceles triangle with round corners and a vertexfacing the second leg.
 4. A clamp according to claim 1, wherein theclamp has a degree of hardness of 43-49 Hardness Rockwell C-scaled.
 5. Aclamp according to claim 1, wherein the remaining part (10) of thematerial around the aperture (5) extends substantially perpendicular tothe plane of the aperture edge (8).
 6. A method for the manufacture of aclamp according to claim 1, the method comprising: that a plane steelsheet blank (1′) with a first and a second end (2′, 3′) is provided, thefirst end (2′) being provided with a throughgoing aperture (5′) with anedge, a part of the material of the blank along the edge extendingtowards the second end (3′) of the blank (1′), and the remaining part(10′) extending around the aperture (5′), that the remaining part (10′)by temperature deformation is bent out of the plane of the blank (1′)and that the blank (1′) is angularly bent.
 7. A method according toclaim 6, wherein the blank (1′) is manufactured with a width which isbigger at the first end (2′) than at the second end (3′).
 8. A methodaccording to claim 6, wherein the blank (1′) is provided with acomparatively narrow aperture (5′) as compared to the aperture of thefinished clamp, which is extended with respect to the width during theheat deformation which is substantially a stretching.
 9. A methodaccording to claim 6, wherein the second end (3′) is provided withimpressions (13) at the sides.
 10. A method according to claim 6,wherein the blank after the moulding is hardened to a degree of hardnessin the range of 43-49 HRC.
 11. An agricultural implement, provided witha member (6) secured on a frame part (7), in which the member (6) issecured by means of a clamp (1) according to claim
 1. 12. A methodaccording to claim 6, wherein said remaining part (10′) is bent to aposition substantially perpendicular to the plane of the blank.
 13. Amethod for the manufacture of a clamp according to claim 1, the methodcomprising: that a plane steel sheet blank (1′) with a first and asecond end (2′, 3′) is provided, the first end (2′) being provided witha throughgoing aperture (5′) with an edge, a part of the material of theblank along the edge extending towards the second end (3′) of the blank(1′), and the remaining part (10′) extending around the aperture (5′),that the remaining part (10′) by temperature deformation is bent out ofthe plane of the blank (1′) and that the blank (1′) is angularly bent;wherein the blank (1′) is provided with a comparatively narrow aperture(5′) as compared to the aperture of the finished clamp, which isextended with respect to the width during the heat deformation which issubstantially a stretching.